On evaporating this solution the hydrated salt CoI 2.6H 2 0 is obtained in hexagonal prisms. It behaves in an analogous manner to CoBr 2.6H 2 0 on heating.
The bisphenoids (the hemihedral forms of the tetragonal and rhombic bipyramids)., and the trigonal pyramid of the hexagonal system, are examples of non-regular tetrahedra (see Crystallography).
103, owing to the silting up of the Claudian harbour, and the increase of trade, to construct another port further inland - a hexagonal basin enclosing an area of 97 acres with enormous warehouses - communicating with the harbour of Claudius and with the Tiber by means of the channel already constructed by Claudius, this channel being prolonged so as to give also direct access to the sea.
On the river bank is a temple to Siva, of hexagonal shape, old and going to ruin.
The surface of a compound eye is seen to be covered with a large number of hexagonal corneal facets, each of which overlies an ommatidium or series of cell elements (fig.
Calcium carbonate separates as hexagonal calcite from cold solutions (below 30°), and as rhombic aragonite from solutions at higher temperatures; lead and strontium carbonates, however, induce the separation of aragonite at lower temperatures.
Telluric acid forms cubic and monoclinic crystals from a hot nitric acid solution, and ammonium fluosilicate gives cubic and hexagonal forms from aqueous solutions between 6° and 13°.
Tutton's investigations of the morphotropic effects of the metals potassium, rubidium and caesium, in combination with the acid radicals of sulphuric and selenic acids, showed that the replacement of potassium by rubidium, and this metal in turn by caesium,was accompanied by progressive changes in both physical and crystallographical properties, such that the rubidium salt was always intermediate between the salts of potassium and caesium (see table; the space unit is taken as a pseudo-hexagonal prism).
PYRRHOTITE, a mineral species consisting of iron sulphide and crystallizing in the hexagonal system.
And a diameter of 16 ft., and is capped with a hexagonal spire of 18 ft., which was added in the 15th century.
They all crystallize in the monoclinic system, often, however, in forms closely resembling those of the rhombohedral or orthorhombic systems. Crystals have usually the form of hexagonal or rhomb-shaped scales, plates or prisms, with plane FIG.
5 and 6), which took the form of simple, incised lines, or bands of shallow oval or hexagonal hollows, was more suited to the material than the deep prismatic cutting of comparatively recent times.
In the interior, which is supported by four pilasters and eight columns, the most striking features are the octagonal font and the hexagonal pulpit, erected in 1260 by Niccola Pisano.
Aurous cyanide, AuCN, forms yellow, microscopic, hexagonal tables, insoluble in water, and is obtained by the addition of hydrochloric acid to a solution of potassium aurocyanide, KAu(CN)2.
It crystallizes in rhombohedra belonging to the hexagonal system, having interfacial angles of 87° 40'.
By heating with sodium amalgam and separating with hydrochloric acid, the dichloride, TaC1 2.2H 2 O, is obtained as emerald green hexagonal crystals.
Freezing takes place by the formation of pure ice in flat crystalline plates of the hexagonal system, which form in perpendicular planes and unite in bundles to form grains so that a thick covering of ice exhibits a fibrous structure.
If the carbonate be in excess, the salt Na4Zr04 results, which when treated with water gives Na2Zr8017 12H20, which crystallizes in hexagonal plates.
Hence, through a triple gateway in a richly ornamented screen, access is gained to the first or Hexagonal Court, which measures about 250 ft.
Hot or dilute cold solutions deposit minute orthorhombic crystals of aragonite, cold saturated or moderately strong solutions, hexagonal (rhombohedral) crystals of calcite.
When dissolved in water it yields some NaOH and H202; on crystallizing a cold 'solution Na202.8H20 separates as large tabular hexagonal crystals, which on drying over sulphuric acid give Na 2 0 2.2H 2 0; the former is also obtained by precipitating a mixture of caustic soda and hydrogen peroxide solutions with alcohol.
Potassium sulphite, K 2 S0 3, is prepared by saturating a potash solution with sulphur dioxide, adding a second equivalent of potash, and crystallizing in a vacuum, when the salt separates as small deliquescent, hexagonal crystals.
On concentration the double salt separates as hexagonal tables.
As the sapphire crystallizes in the hexagonal system it is dichroic, but in pale stones this character may not be well marked.
The Helena crystals are of tabular habit, being composed of the basal pinacoid with a very short hexagonal prism, whilst at Yogo Gulch many of the crystals affect a rhombohedral habit.
In the amorphous state it is a dull green, almost infusible powder, but as obtained from chromium oxychloride it is deposited in the form of dark green hexagonal crystals of specific gravity 5 2.
In book v., after an interesting preface concerning regular polygons, and containing remarks upon the hexagonal form of the cells of honeycombs, Pappus addresses himself to the comparison of the areas of different plane figures which have all the same perimeter (following Zenodorus's treatise on this subject), and of the volumes of different solid figures which have all the same superficial area, and, lastly, a comparison of the five regular solids of Plato.
By - adding sodium phosphate to magnesium sulphate and allowing the mixture to stand, hexagonal needles of MgHPO 4.7H 2 O are deposited.
The Grey Friars at Lynn, where the tower is hexagonal, is a good example.
The choir is long and aisleless; an hexagonal tower between the two, like that existing at Lynn, has perished.
The usual form of ice-crystals in clouds is a right hexagonal prism, which may be elongated as a needle or foreshortened like a thin plate.
The anthelion (a) may be explained as caused by two internal reflections of the solar rays by a hexagonal lamellar crystal, having its axis horizontal and one of the diagonals of its base vertical.
Chemie, 1886, 25, p. 118); it forms hexagonal crystals which melt at 1.6° C.
The substance is usually optically isotropic, though sometimes it exhibits anomalous double refraction; fibrous zinc sulphide which is doubly refracting is to be referred to the hexagonal FIG.
120-127) has obtained it in lustrous hexagonal crystals by electrolysing the double fluoride of beryllium and sodium or potassium with an excess of Crystal of beryl.
Beryllium oxide, beryllia or glucina, BeO, is a very hard white powder which can be melted and distilled in the electric furnace, when it condenses in the form of minute hexagonal crystals.
The hydroxide is obtained as brown hexagonal plates by fusing thallic oxide with potash to which a little water has been added.
The cells of the honeycomb of Apis are usually hexagonal in form, and arranged in two series back to back (figs.
It forms microscopic hexagonal plates having a silver-white streak.
It forms large colourless hexagonal crystals.
The upper town contains the hexagonal piazza, a citadel, erected in 1573 by Emanuel Philibert, the cathedral of S.
Thus in the hexagonal frame of fig.
The extreme upper end of the arbor, which was hexagonal, received a head, which was really a lever of some length; this head was connected by a coupling-bar to a similar lever or head, into which the upper end of the spindle was inserted.
Hence if we take two nets of wire with hexagonal meshes, and place one on the other so that the point of concourse of three hexagons of one net coincides with the middle of a hexagon of the other, and if we then, after dipping them in Plateau's liquid, place them horizontally, and gently raise the upper one, we shall develop a system of plane laminae arranged as the walls and floors of the cells are arranged in a honeycomb.
The crystal, from Elba, shows a combination of the fundamental rhombohedron (R), an obtuse rhombohedron (s), and the hexagonal bipyramid (n).
The so-called "iron roses" (Eisenrosen) of Switzerland are rosette-like aggregates of hexagonal tabular crystals, from fissures in the gneissose rocks of the Alps.
This is illustrated by the hexagonal pyrargyrite 3Ag 2 S Sb 2 S 3, and proustite, 3Ag 2 S As2S3, and the monoclinic pyrostilpnite, isomeric with pyrargyrite, and xanthoconite, isomeric with proustite.
AgI, occurs in nature as the mineral iodargyrite or iodyrite, forming hexagonal crystals, or yellowish green plates.
Silver iodide is dimorphous; at ordinary temperatures the stable form is hexagonal; on heating to about 138° the colour changes from deep yellow to yellowish-white with the formation of cubic crystals.
The acid crystallizes in hexagonal prisms and melts at 58° C. It dissolves in water and yields a hydrate of composition H 2 SeO 4 H 2 O.